<nav class="nav">
        <input type="checkbox" id="nav-toggle" class="nav-toggle">
        <label for="nav-toggle">
            <svg xmlns="http://www.w3.org/2000/svg" width="23" height="22">
                <defs>
                    <filter id="shadow">
                        <feDropShadow dx="0" dy="0" stdDeviation="1.6">
                    </filter>
                </defs>
                <polygon points="1,1 22,10 1,20 1,1" fill="#1d7ad9" filter="url(#shadow)"></polygon>
            </svg>
        </label>
        <ul class="nav-list">
            <li>
                <a href="#">首页</a>
            </li>
            <li>
                <a href="#">在线定制</a>
            </li>
            <li>
                <a href="#">标准箱</a>
            </li>
            <li>
                <a href="#">品质保障</a>
            </li>
        </ul>
    </nav>
    <main class="main">
        <div class="step-box">
            <div class="step">
                <div class="circle" id="box-circle">1</div>
                <div class="line" id="box-line"></div>
                <p id="step-one">1.定制纸箱</p>
            </div>
            <div class="step">
                <div class="circle" id="size-circle">2</div>
                <div class="line" id="size-line"></div>
                <p id="step-two">2.选择数量</p>
            </div>
            <div class="step">
                <div class="circle" id="material-circle">3</div>
                <div class="line" id="material-line"></div>
                <p id="step-three">3.上传附件</p>
            </div>
            <div class="step">
                <div class="circle">4</div>
                <div class="line"></div>
                <p>4.确认下单</p>
            </div>
        </div>